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A058118
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Triangle: self-converse semigroups of order n with k idempotents.
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4
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1, 2, 1, 5, 5, 2, 18, 24, 16, 6, 93, 123, 112, 58, 19, 930, 754, 764, 542, 254, 68, 22899, 6721, 5567, 4751, 2933, 1214, 285, 1937266, 123988, 49969, 41939, 31392, 17396, 6513, 1376, 613365656, 8265721, 739317, 410158, 328937, 223226, 113160, 38979, 7510
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Andreas Distler, Classification and Enumeration of Finite Semigroups, A Thesis Submitted for the Degree of PhD, University of St Andrews (2010).
Index entries for sequences related to semigroups
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EXAMPLE
| 1; 2,1; 5,5,2; 18,24,16,6; 93,123,112,58,19; ...
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CROSSREFS
| Row sums give A029851. Main diagonal: A058122. Columns 1-3: A058119-A058121.
Sequence in context: A118244 A108410 A058116 * A124226 A193536 A152290
Adjacent sequences: A058115 A058116 A058117 * A058119 A058120 A058121
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KEYWORD
| nonn,tabl,hard
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AUTHOR
| Christian G. Bower (bowerc(AT)usa.net), Nov 10 2000
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EXTENSIONS
| More terms from Andreas Distler (andreas(AT)mcs.st-andrews.ac.uk), Jan 13 2011
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